Laurence D. Fink, chief executive officer of BlackRock Inc., said in a time of global upheaval -- from Brexit to the election of Donald Trump -- it’s imperative that companies constantly assess their strategy and adapt to changing markets. In his annual letter to CEOs posted on the firm’s website Tuesday, Fink said BlackRock will keep a close eye on how companies are responding to this environment where there is a growing backlash against the impact of globalization and technological change...